Method and apparatus for recycling wash chemicals used in powder coating

ABSTRACT

The invention relates to a method and apparatus for recycling a wash solution used in powder coating which uses filters. The invention also relates to methods and apparatuses for recycling wash solutions used in spray washing, steam cleaning or car washes using filters.

This application claims priority to U.S. Provisional Application Nos.60/411,382, filed Sep. 18, 2002; 60/408,281, filed Sep. 6, 2002;60/406,059, filed Aug. 27, 2002; 60/404,403, files Aug. 20, 2002; and60/402,526, filed Aug. 12, 2002, the complete disclosures of which areincorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a method and apparatus for recycling a washsolution used in powder coating. The invention also relates to methodsand apparatuses for recycling wash solutions used in spray washing,steam cleaning or car washes.

BACKGROUND OF THE INVENTION

The method of powder coating an object to form a paint coating thereonis well known. Such powder coating techniques require a washing step toremove oils and dirt that would inhibit the bonding of the power coatingto the surface of the object to be coated. It is now well known to use apower washer to dislodge oil and dirt from the object to be coated.Depending on the geographic location, iron phosphate, potassiumphosphate and/or sodium phosphate (hereinafter referred to as phosphatecollectively) is usually added to the wash solution used in spraywashing to facilitate the removal of the oil and dirt.

A typical powder coating company uses from 15,000 to 18,000 gallons ofwater and 125 to 175 gallons of phosphate per month in the washingprocess of powder coating. This used wash solution of wash water andchemicals is usually discharged through municipal waste systems.

There have been attempts to recycle the used wash solution. One suchconventional recycling apparatus is sold commercially under theCyclonator™ name. A description can be found on the internet atwww.cyclonator.com. This system uses numerous hoses to and from aspecially designed washing platform, an additional separate filteringtank to remove larger debris and oils, a special holding tank, and twovacuum canister type filters that require expensive filters. Thisrecycling apparatus provides no visual monitoring ability except forvacuum gauges, has no pH monitoring nor automatic adjustment capability,and the location of the unit has to be in close proximity to the washplatform and the power washer. Furthermore, the recycling apparatus isdifficult to maintain, requires a large area of space and numerous extraequipment at additional cost. Moreover, the vacuum used to force thewash solution through a filter can undesirably force dirt throughfilters.

There is a need for an improved recycling apparatus that does notrequire a vacuum, provides easy visual inspection of the filters duringoperation, is easy to maintain and operate, is compatible with the widerange of wash platforms currently used, and can be scaled to any sizepowder coating operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side view of the recycling apparatus;

FIG. 2 illustrates a top view of the recycling apparatus;

FIG. 3 illustrates a side view of a wash solution agitator;

FIG. 4 illustrates a side view of a distributing pipe;

FIG. 5A illustrates a cutaway, side view of a filter assembly;

FIG. 5B illustrates a top view of the bottom strap for holding a filter;

FIG. 5C illustrates an end view of a filter assembly;

FIG. 6 illustrates a spray wash assembly utilizing a recyclingapparatus;

FIG. 7 illustrates a side view of another embodiment of the recyclingapparatus;

FIG. 8 illustrates a side view of a further embodiment of the recyclingapparatus;

FIG. 9 illustrates a top view of a further embodiment of the recyclingapparatus;

FIG. 10 illustrates a side view of an agitator;

FIG. 11 illustrates a view of a distributing pipe;

FIG. 12 illustrates a cutaway side view of a filter assembly;

FIG. 13 illustrates a top view of a bottom strap for holding a filter;

FIG. 14 illustrates a cutaway side view of an oil separator tank;

FIG. 15 illustrates a view of a holding tank;

FIG. 16 illustrates a cutaway side view of an oil separator tank;

FIG. 17 illustrates a side view of a main tank;

FIG. 18 illustrates a side view of a protecting tank;

FIG. 19 illustrates a cutaway view of a corner seam on a protectingtank; and

FIG. 20 illustrates a spray wash assembly utilizing a recyclingapparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described with reference to preferredembodiments as shown in the Figures. The claimed invention is notlimited to these preferred embodiments.

As shown in FIG. 1, the recycling apparatus 1 comprises a main tank 2that is about three feet wide, about three feet deep, and about fivefeet long. The exemplary main tank 2 is sized to operate with onestandard spray washer operating at a maximum of about 5 gallons perminute. The main tank 2 can be sized for any desired flow rate andnumber of spray washers.

The main tank 2 is constructed of 14 gauge mild steel, but can beconstructed of any desired material that is suitable to hold the usedwash solution. Examples of suitable materials include, but are notlimited to, metals, alloys, rubbers, plastics, glass, coated wood, orfiberglass. Preferably, if metal parts are utilized in the recyclingapparatus 1, the metal parts are powder coated to prevent rust.

Wash solutions are well-known and any conventional wash solution can beused in the present recycling apparatus. The wash solution is usuallyacidic. A preferred wash solution contains phosphate. The wash solutionis preferably free-of chemicals that cannot be recycled, such as butylcellusolve (a glycol ether), which can vaporize or break down at 175° F.and cause undesirable vapors during spray washing. Preferably, the washsolution is free-of heavy metals such as molybdate, that areenvironmentally unfriendly. A suitable commercially available phosphatethat can be combined with water to form the wash solution is sold underthe name DuBoise Diversy/Lever, secure steam ultra.

The main tank 2 is split into three separate tanks for holding the washsolution, holding tanks 4 and 6, and recycled wash solution tank 8, bybaffles 10 and 12. The baffles can be formed from the same material asthe holding tank, or any material suitable to hold wash solution. Ifdesired, separate tanks can be used instead of splitting one large tankinto smaller tanks with the use of baffles, as described herein below.

Each tank 4, 6 and 8 has an associated filter assembly 30, 32 and 34.Three tanks and filter assemblies is the preferred arrangement. However,if more filtering is desired, the number of tanks and associated filterassemblies can be increased. While not preferred, if less filtering isdesired, the number of holding tanks can be reduced to one.

The first holding tank 4 has a used wash solution inlet 21 connected toa distributing pipe 22 using a quick disconnect 23. As shown in FIG. 4,the distributing pipe 22 is about 2 to 4 feet in length, about 1 inch indiameter and has a plurality of drain holes 26 spaced the length thatare about ¼ to about ⅜ inch in diameter. The distributing pipe 22 issupported by a support 24. The size and length of the distributing pipe22 and the size and number of drain holes 26 can be varied as desiredfor the particular application. Preferably, the distributing pipe 22 isconstructed to evenly distribute the used wash solution over the filterassembly 30 to maximize the life of the filter. The end of thedistributing pipe 22 can be capped or left open as desired. Thedistributing pipe 22 can be formed from any material that is suitablefor holding wash solution. The baffles 10 and 12 are staggered inheight, with the height of baffle 10 being higher than baffle 12 so thatthe wash solution level in tank 4 is higher than the wash solution levelin tank 6 and the wash solution level in tank 6 is higher than the washsolution level in tank 8. The baffles 10 and 12 each have associatedoutlets 14 and 16 located about 1 inch below the top of each bafflethrough which the wash solution can flow. The outlets 14 and 16 eachhave associated 1 inch diameter pipes 18 and 20 respectively. As shownin FIG. 2, there are four outlets 14 having four associated pipes 18 andfour outlets 16 having associated pipes 20 that spaced apart the widthof the main tank 2. The pipes 18 and 20 are about 1 inch in diameter andcan be formed from any material that is suitable for holding washsolution. The pipes 18 and 20 terminate at about the mid point axis ofthe respective tank 6 and 8. The size, number and location of pipes 18and 20 can be varied as desired. Preferably, the size, number andlocation of the pipes 18 and 20 are such that the wash solution isspread evenly over the filter assemblies to maximize the filterlifetime. If desired a conduit can be used in place of the pipes 18 and20, which spreads the solution evenly over the filter assembly.

Each tank 4, 6 and 8 has an associated filter assembly 30, 32 and 34.The filter assemblies 30, 32 and 34 are sized to removably fit withintheir respective tank, as shown in FIGS. 1 and 2. As shown in FIGS.5A-5C, the filter assembly 30 comprises 2 inch expanded steel mesh 40 inthe shape of a half circle having a 4 inch diameter 42, a ⅛×1 inchI-shaped strap 42 that can be welded to the steel mesh 40, a filter 44,and two ⅛×1 inch straps 46 at each end of the filter assembly 30. Thefilter 44 is held in place by fastening the straps 46 to the I-shapedstrap 42 using bolts 50. While the use of bolts and straps are shown inthe FIGS., the filter can be held in place using any suitable means,such as clamps, clasps, screws, and ties. The ends of the filterassembly 30 are sealed using 4×8 inch plates 54. The filter assembly 30is removably held in place within tank 4 using the four mounting straps56 that can be clasped to the main tank walls 2. The mounting straps canbe held in place by gravity such that the filter assembly can easily beraised out of the tank, or held in place by using any suitable fasteningmeans, such as bolts, screws, clasps and clamps. Any number of mountingstraps can be used. Alternatively, instead of mounting straps 56, thefiltering assembly can rest on stops placed in the tank to hold it inplace instead of hanging the filtering assembly on mounting straps 56.Each of the filter assemblies 32 and 34 are similar in construction tothe filter assembly 30, except for the length of the mounting straps 56.The mounting straps 56 should be of a length such that during operationwash solution flows from the pipes 22, 18 and 20 into the respectivefilter assemblies and filtered wash solution drops from the filterassemblies into their respective tanks.

The filter assemblies and tanks are constructed and arranged such thatduring operation, the filtered wash solution drops about 1 inch to 30inches, more preferably from about 2 inches to about 24 inches, morepreferably from about 3 inches to about 12 inches, and most preferablyabout 6 to about 8 inches, before contacting the surface of the washsolution in the respective tank to provide aeration. The height of thefiltering assembly can easily be adjusted by adjusting the length of themounting straps 56 and/or adjusting the height of the baffles and 10 and12 and their associated outlets 14 and 16.

The size and structure of the filter assembly can be varied as desired.Preferably, the size of the filter should be such that at least a 5gallon per minute flow rate is provided under ambient pressure andgravity.

The preferred filter assembly shown uses a flat rolled filter 44, whichcan be purchased in spools three feet wide and 150 feet long and easilycut to the proper length. The filters usually last about 1 week induration before changing is required, but should be monitored daily. Tochange the filter in filter assembly 30, the distributing pipe 22 isfirst removed by removing the quick disconnect 23 and the mountingstraps 56 are then unclasped and filter assembly 30 lifted out. Tochange the filters in filter assemblies 32 and 34, the mounting straps56 are unclasped and the filter assembly 32 or 34 tilted to clear therespective pipe 18 or 20 and lifted out.

Once the filter assembly is out of the tank, the filter 44 can be easilyreplaced by removing the bolts 50 and lifting the used filter 44 out thefilter assembly. A new filter 44 can be easily cut to the proper lengthfrom a spool of filter, placed in the filter assembly, and securelymounted using the straps 46 and bolts 50. The filter assembly can beeasily replaced in the tank by reversing the steps for removing thefilter assembly.

The preferred filter 44 is inexpensive and easily obtained fromcommercial manufacturers or from a filter supply company. The spool isusually three (3) feet wide and one hundred fifty (150) feet long.Examples of preferred commercially available filter materials include,but are not limited to, the BR-60 and BR-80 series from Mountain StatesFilter, Colorado. While inexpensive flat sheets of filter cloth arepreferred filters, any suitable filter material can be used as desiredfor the particular application.

The filter can be selected by the end user to provide the desired levelof filtering based on the particular application. It has been found thatfilters having a size of less than 10 microns are suitable. A preferredarrangement is the use of a filter having a size of about 3 to 8 micronsin the filter assembly 30, and about 1 microns or less in each of thefilter assemblies 32 and 34. However, the size of the filter can bevaried as desired for the particular application.

The first and second baffles 10 and 12 can optionally contain aseparator shield that is designed to isolate oils, which can then bemechanically or manually removed.

The recycled wash solution tank 8 contains the filtered recycled washsolution that can be reused in the spray washer. As shown in FIGS. 1 and6, a ¼ hp submersible pump 60 is located in the recycled wash solutiontank 8, which pumps the recycled wash solution to the power washer 100via hose 90. The sump pump is controlled by panel 84. While a sump typepump is shown, any suitable pump can be used, such as an air operateddiaphragm style pump that is external or internal to the tank 8. In theair operated diaphragm style pump, no electricity is involved, whichfurther enhances the safety of the apparatus. Hose 90 is connected tothe hose connection 89.

To prevent sediment buildup in the tanks 4, 6 and 8, the pump 60 isconnected to agitators 70 and 72 via line 74 to pump recycled washsolution in tank 8 to the holding tanks 4 and 6. If desired a separatepump can be used to feed the agitators 70 and 72. A valve 76 regulatesthe amount of wash solution pumped to the agitators 70 and 72. As shownin FIGS. 1 and 3, the agitator 70 is formed from a 1 inch square pipethat has been capped at both ends. A plurality of ¼ to ⅜ inch holes 75are spaced the length of the agitator 70. The agitator 70 is about thesame width of the holding tank 4. The size, shape and number of theagitators 70 and 72 can be varied as desired for the particularapplication. If more agitation is desired, a larger agitator, multipleagitators or smaller holes 75 can be used. If less agitation is desired,a smaller agitator or larger holes 75 can be used. When recycled washsolution is pumped into the agitator 70, it is sprayed out of the holes75 and agitates the wash solution present in the holding tank 4. Theagitator 72 works in the similar manner. If precipitates form in therecycled wash solution tank 8, they can be pumped into the holding tanks4 and/or 6 via the agitators 70 and 72 and then caught by the respectivefilter assemblies. The agitators can be run continuously, even when thespray washer is not used, to remove undesirable precipitates and preventsediment buildup in the tanks.

While recycling recycled wash solution from the recycled wash solutiontank 8 is preferred for agitation and removal of precipitates, washsolution from other tanks can be utilized, such as using wash solutionin the second holding tank 6 to supply the agitator in the first holdingtank 4.

The recycling apparatus 1 preferably contains a water level monitor 85in the recycled wash solution tank 8 to alert the user of low washsolution conditions. If desired, the water level monitor 85 can beconnected to a water supply to automatically add water to the recycledwash solution tank 8 through inlet 86 as needed. The water level monitor85 can be any conventional water level monitor, such as commonly used intoilets or the well-known water levelers used in the commerciallyavailable Swamp Cooler™.

During operation, the recycling apparatus 1 is connected to a powerwasher 800 using a hose 90. The sump pump 60 pumps recycled washsolution to the power washer 800 at a pressure of about 5 pounds persquare inch (psi) or greater. The capacity of the sump pump 60 can beadjusted to match the input pressure requirements of the particularspray washer being utilized. The power washer 800 heats the washsolution to any desired pressure and temperature, for example, about 180to about 220° F. and about 1500 to about 3000 psi. The object to bewashed is sprayed with the heated pressurized wash solution in the washarea 810 using the wand 806. The used wash solution is collected and thedirt separated therefrom using the screens 811. The screened used washsolution is then pumped to the inlet 21 of the recycling apparatus usingthe pump 812 and line 814 in a continuous loop.

During operation, it has been found that the pH of the recycled washsolution can vary. Preferably, the recycling apparatus comprises a pHmonitor 83 which monitors the pH of the recycled wash solution in therecycled wash solution tank 8 using the probe 87. If the pH is too high,the pH monitor adds phosphate to the recycled wash solution tank 8 viaphosphate inlet 88 until the desired pH is reached. The pH can also bemonitored and adjusted manually if no pH monitor is present. Preferably,the pH of the wash solution in the recycled wash solution tank 8 ismaintained such that it is high enough to avoid causing significant ruston the part being cleaned and low enough to provide sufficient cleaning.It has been found that when phosphate is used, the pH should be between4.5 and 6.5, more preferably between about 5 to about 6, and mostpreferably about 5.5 to provide sufficient cleaning and avoid causingsignificant rust on the part being cleaned. These pH ranges apply to apowder coating process utilizing phosphate. If other chemicals are used,or different cleaning techniques are utilized, the pH can easily betailored to any desired range by using common techniques of adding basesto increase the pH and acids to decrease the pH.

The pH monitor 83 preferably has a digital readout of the pH orsetpoint. This will allow for high accuracy in maintaining theappropriate acidity necessary to properly clean the product to beserviced. While this example uses phosphate, other pH adjustingchemicals can be used as desired for the particular application.

Any phosphate suitable for spray washing for powder coating applicationscan be used. The type of phosphate used will usually depend on thehardness of the water as it varies by geographic location. The wassolution can also contain conventional cleaning agents, such asmolybdates, if desired.

FIG. 7 illustrates a preferred embodiment in which no high-voltageelectricity is utilized in the recycling apparatus 1 to provide enhancedsafety. In place of the electrically driven sump pump 60 a pressurizedair operated pump 61 is utilized. Commercial examples of suitable airoperated pumps 61 include those sold under the Ingersoll-Rand ARO line,such as the Model 6660. The air operated pump 61 is preferably mountedinside the recycled wash solution tank 8 so that if there are any leaksin the pump 61 they will be contained. However, if desired, the pump 61can be mounted external to the recycling apparatus 1. The pump 61 ispowered by pressurized air supplied by line 65 and pressurized airconnector 63 from an air compressor (not shown). Conventional powdercoating operations usually utilize an air compressor that can be easilytapped to power the pump 61. The speed of the pump 61 can be regulatedby the regulator 67. The regulator 67 can contain an air filter ifdesired. The pump 61 operates in the recycling apparatus 1 in the samemanner as the pump 60 as described herein above.

Also shown in FIG. 7, is the preferred arrangement of the pH meter 83being located on the phosphate tank 62 and having a pump associatedtherewith. When the pH meter 83 detects that the pH level is too high bythe probe 87 connected by line 66, phosphate is pumped from the tank 62to the recycled wash solution tank 8 via line 64 and inlet 88 until thedesired pH is reached.

The lid 3 covers the main tank 2 and is preferably of a see-thru typematerial to allow easy visual inspection of the filter assemblies andthe fluid levels during operation. The lid 3 can be one solid piece ormultiple pieces so that access to each holding tank can be separatelyobtained. The lid 3 can be hinged if desired, but is preferably slidablymounted or mounted to be lifted off to allow easy and safe access to thefilters and the separator areas.

The recycling apparatus and method described herein is environmentallyfriendly. Bacterial and fungus buildup in the recycling apparatus issubstantially avoided without the use of environmentally unfriendlychemicals by a combination of the see through lid that allows light toenter, the continuous aeration in each of the tanks 4, 6 and 8, andfiltering. The phosphate, which is the same type (only stronger) as usedin laundry and dish washers as a cleaning and disinfecting agent, willhelp kill the bacteria. Furthermore, the high temperature achieved inthe power washer will kill even more bacteria.

Before I designed the present recycling apparatus, I was using 15,000 to18,000 gallons of water and 125 to 175 gallons of phosphate per month inthe process of powder coat painting. Now I use about 1,500 gallons ofwater and about 5 to about 10 gallons of phosphate per month. Icurrently recommend that the about ½ of the wash solution be replacedeach month. However, I have run the recycling apparatus up to 3 monthswithout removing any wash solution from the recycling apparatus, evenunder heavy use. The time between such replacement will vary dependingon the use of the recycling apparatus.

The state of Colorado is currently in an extreme drought condition andthe land my business is located on does not accommodate leaching a largeamount of water discharge through the sewage leach field. Public sewageis not at this time within reach. With my new recycling apparatus, thewastewater and the drought are no longer an issue.

FIGS. 8-20 illustrate a further embodiment of the invention whichutilizes a retaining container 104 and removable tanks 150, 160, and170.

As shown in FIGS. 8 and 9, the recycling apparatus 9 comprises a maintank 102 that is about 9 feet wide 302, about 6 feet high 305, and about12 to about 20 feet long 301. If the recycling apparatus is wider than 9feet, preferably it is structure such that one dimension is 9 feet orless so that it can be shipped without using the more expensive wideload requirements. The exemplary main tank 102 is sized to operate withone to five standard spray washer operating at about 5 gallons perminute. The main tank 102 can be sized for any desired flow rate andnumber of spray washers.

The main tank 102 is constructed of reinforced 14 gauge mild steel, butcan be constructed of any desired material that is suitable to hold theused wash solution. Wash solutions are well-known and any conventionalwash solution can be used in the present recycling apparatus. The washsolution is usually acidic. A preferred wash solution containsphosphate. Examples of suitable materials to hold the wash solutioninclude, but are not limited to, metals, alloys, rubbers, plastics,glass, coated wood, or fiberglass.

The main tank 102 is reinforced by folding the sheet metal over to forma top edge 600 as shown in FIG. 17. The sides are also reinforced withangle iron 601 to reduce any bowing of the sides caused by the weight ofthe wash solution contained therein during use. Depending on the size ofthe recycling apparatus, more or less reinforcing may be needed toreduce bowing of the sides.

The main tank 102 is surrounded on all four sides and the bottom by aprotecting tank 104, which has side panels 250, 251, 252 and 253 abottom panel 254. The protecting tank 104 is designed to retain anyleaks in the main tank 102 and to protect the main tank 102 from damage,such as from vehicles hitting the sides. The exemplary protecting tank104 is formed from 14 gauge steel, but can be formed from any suitablematerial. As shown in FIG. 18, the protecting tank 104 is reinforcedusing the top angle iron 620 and a side angle iron 622. The amount ofreinforcing can be increased or decreased as needed to prevent bowing.The protecting tank 104 preferably contains a drain 107 and drain valve106.

The protecting tank 104 is designed such that if any side panel 250,251, 252, or 253 is damaged it can easily be replaced. As shown in FIG.19, the side panel 253 is welded to one side of a 2 inch angle iron 851by welds 855, which travel the length of the angle iron 851 to preventleaks. The side panel 253 contains holes through which the bolts 861 canpass. The angle iron 851 contains nuts 859 welded thereto by welds 860.The side panel 250 is welded to another 2 inch angle iron 850 by welds856 that travel the length of the angle iron 850 to prevent leaks. Theside panel 250 contains holes through which the bolts 864 can pass. Theangle iron 850 contains nuts 867 welded thereto by welds 863. The nuts867 are arranged to accept bolts 861 and the nuts 859 are arranged toaccept bolts 864 when the panels 250 and 253 are in alignment. In thismanner a leak proof seal is formed at each corner of the holding tank104.

The tanks 102 and 104 are powder coated with epoxy paint to preventrust. To reduce wear during use, a cushion 900 is located between thetank 102 and tank 104. The cushion can be any suitable material, such asplastics, rubbers or wood. A layer of plastic pipes is also suitable.

The main tank 102 is split into four separate tanks for holding the washsolution by three removable tanks, oil separator tank 150, first holdingtank 160 and second holding tank 170. A recycled wash solution tank 190surrounds the three removable tanks and is defined by the outsidesurfaces of the tanks 150, 160 and 170 and by the inside surface of themain tank 102.

The removable tanks can be formed from the same material as the maintank 102, or any material suitable to hold wash solution. If desired,separate tanks can be used instead of splitting one large tank intosmaller tanks with the use of baffles. However, the use of one largetank as shown in the drawings is preferred.

The oil separator tank 150 is formed from 14 gauge steel, but can beformed from any suitable material. The tank 150 is about 2 feet wide, 8feet long and about 6 feet high. The sides of the tank 150 arereinforced in a manner similar to the first holding tank 160 shown inFIG. 16, and described below.

The oil separator tank 150 has a mesh 155 to catch dirt and largeparticles. As shown in FIG. 14, a wave suppressor 157 is present in thetank 150 to prevent waves caused by inflow of used wash solution throughline 151 from reaching the oil skimmer 152. The wave suppressor 157 is a4 inch high sheet metal that sits about 1 to 2 inches below the surfaceof the used wash solution, shown at 320, during operation. Oil skimmedfrom the surface by the oil skimmer 152 during operation can be pumpedto a waste drum by the line 158.

The holding tanks 160 and 170 are formed from 14 gauge steel, but can beformed from any suitable material. The tanks 160 and 170 are each about8 feet long 334 and 3 feet wide 330. The tank 160 is about 6 feet high.The tank 170 is about 12 inches less in height than the tank 160. Thetanks 160 and 170 have associated pipes 166 and 176 respectively. Thelength of the pipes 166 is such that they empty at about the center axisof the tank 170 to evenly distribute the wash solution over the filterassembly 172, when the tanks 160 and 170 are in position in the maintank 102. Similarly, the pipes 176 have a length such that when the tank170 and filter assembly 182 are in position in the main tank 102, thepipes 176 empty wash solution from the tank 170 into the central axis ofthe filter assembly 182 to evenly distribute the wash solution over thefilter assembly 182. The pipes 166 and 176 are about 1 inch in diameterand protrude about 1.5 feet from the side of the tank. The pipes 166 and176 are spaced to distribute the wash solution over the length of thefilter. The number of pipes 166 and 176 can be varied as desired. Thepipes 166 and 176 can be replaced with any suitable conduit for troughfor directing the flow of the wash solution to the associated filteringassembly. The tanks 160 and 170 can optionally have a lifting hole 450if desired to facilitate lifting of them out of the main tank 102 duringmaintenance.

The tanks 160, 170 and 190 are preferably powder coated if they are madeof a material that can rust, such as mild steel. During operation, therecycling apparatus may have vibrations. To reduce the wear on thepowder coating surface, cushions 902, 904 and 906 are installed betweenthe tanks 160, 170 and 180 and the inside surface of the main tank 102.The cushions can be formed from any material suitable to reduce wear,such as plastics, rubbers, or wood. A layer of plastic pipes have beenused for this purpose.

Each tank 160,170 and 190 has an associated filter assembly 162 172 and182. Three tanks and filter assemblies is the preferred arrangement.However, if more filtering is desired, the number of tanks andassociated filter assemblies can be increased. While not preferred, ifless filtering is desired, the number of holding tanks can be reduced toone.

Oil reduced wash solution is supplied from the bottom of the bottom ofthe oil separator tank by entering the intake 128, flowing through line130, first pump 126, line 132 and then being distributed by adistributing pipe 134 over the filter assembly 162. As shown in FIGS. 8and 11, the distributing pipe 134 is about 7 feet in length, about 1inch in diameter and has a plurality of drain holes 136 spaced thelength that are about ¼ to about ⅜ inch in diameter. The distributingpipe 134 is supported by supports 135 that rest on a top surface of thefilter assembly 162 during operation. The size and length of thedistributing pipe 134 and the size and number of drain holes 136 can bevaried as desired for the particular application. Preferably, thedistributing pipe 134 is constructed to evenly distribute the used washsolution over the filter assembly 162 to maximize the life of thefilter. The end of the distributing pipe 134 can be capped or left openas desired. The distributing pipe 134 can be formed from any materialthat is suitable for holding wash solution.

The first pump 126 is preferably an air driven diaphragm type pump. Thepump 126 is connected to a pressurized air source by the distributiontee 701 and has an associated valve and filter 706 to regulate the flowof wash liquid. While an air pump is preferred, any type of pump can beused as desired. The pump 126 is preferably contained within the tank190 so that if a leak occurs in the pump 126 or associated line it willbe contained in the tank 190.

The pipes 166 and 176 are staggered in height, with the height of pipes166 being higher than pipes 176 so that the wash solution level in tank160 is higher than the wash solution level in tank 170 and the washsolution level in tank 170 is higher than the wash solution level intank 190.

Each tank 160 and 170 has an associated filter assembly 162 and 172. Thefilter assemblies 160 and 170 are sized to removably fit within theirrespective tank, as shown in FIGS. 8 and 9. As shown in FIGS. 8, 9, 12,and 13, the filter assembly 162 comprises 2 inch expanded steel mesh400, a ⅛×1 inch I-shaped strap 402 that can be welded to the steel mesh400, a filter 404, and two ⅛×1 inch straps 406 at each end of the filterassembly 162. The filter 404 is held in place by fastening the straps406 to the I-shaped strap 402 using bolts 410. While the use of boltsand straps are shown in the FIGS., the filter can be held in place usingany suitable means, such as clamps, clasps, screws, and ties. Anoptional top clamp is shown at 409 that is held in place by bolts 408.The ends of the filter assembly 162 are sealed using plates 167. Thefilter assembly 162 is removably held in place within tank 160 using thearms 164 by gravity such that the filter assembly can easily be raisedout of the tank, or held in place by using any suitable fastening means,such as bolts, screws, clasps and clamps. Alternatively, instead of arms164, the filtering assembly 162 can rest on stops placed in the tank 160to hold it in place. The filter assemblies 172 and 182 have the sameconstruction as the filter assembly 162.

The filter assembly 182 is held in place by a rack 180 mounted in themain tank 102. The filter assembly 182 sits in the rack 180 and is heldin place using arm similar to those shown at 164 in FIG. 12.

The height of the tanks 160 and 170 and pipes 166 and 176 should be suchthat during operation wash solution flows from the pipes 166 and 176into the respective filter assemblies and filtered wash solution dropsfrom the filter assemblies into their respective tanks by gravity feed.

The filter assemblies and tanks are constructed and arranged such thatduring operation, the filtered wash solution drops about 1 inch to 30inches, more preferably from about 2 inches to about 24 inches, morepreferably from about 3 inches to about 12 inches, and most preferablyabout 6 to about 8 inches, before contacting the surface of the washsolution in the respective tank to provide aeration. The height of thefiltering assembly can easily be adjusted by adjusting the height of thetank and/or adjusting the length of the arms 164.

The size and structure of the filter assembly can be varied as desired.Preferably, the size of the filter should be such that at least a 5gallon per minute flow rate is provided under ambient pressure andgravity, and more preferably at least a 20 gallon per minute flow rateis provided.

The preferred filter assembly shown uses a flat rolled filter 404, whichcan be purchased in spools three feet wide and 150 feet long and easilycut to the proper length. The filters usually last about 1 week induration before changing is required, but should be monitored daily. Tochange the filter in filter assembly 162, the filter assembly 162 islifted out of tank 160, or can be changed while still in the tank 160 ifdesired.

Once the filter assembly is out of the tank, the filter 404 can beeasily replaced by removing the bolts 410 and lifting the used filter404 out the filter assembly. A new filter 404 can be easily cut to theproper length from a spool of filter, placed in the filter assembly, andsecurely mounted using the straps 406 and bolts 410. The filter assemblycan be easily replaced in the tank by reversing the steps for removingthe filter assembly.

The filter 404 is inexpensive and easily obtained from commercialmanufacturers or from a filter supply company. The spool is usuallythree (3) feet wide and one hundred fifty (150) feet long. Examples ofcommercially available filter materials include, but are not limited to,the BR-60 and BR-80 series from Mountain States Filter, Colorado.

The filter can be selected by the end user to provide the desired levelof filtering based on the particular application. It has been found thatfilters having a size of less than 10 microns are suitable. A preferredarrangement is the use of a filter having a size of about 3 to 8 micronsin the filter assembly 162, and about 1 microns or less in each of thefilter assemblies 172 and 182. However, the size of the filter can bevaried as desired for the particular application.

The recycled wash solution tank 190 contains the filtered recycled washsolution that can be reused in a spray washer. As shown in FIGS. 8, 9,and 20, a second pump 110 is located in the recycled wash solution tank190, which pumps the recycled wash solution to a hose connection 114, towhich power washers 800 can be connected via hose 802.

The second pump 110 is preferably an air driven diaphragm type pump. Thepump 110 is connected to the distribution tee 700 by line 704 and has anassociated valve and filter 706 to regulate the flow of wash liquid.Pressurized air is supplied to the tee 701 by the line 700. While an airpump is preferred, any type of pump can be used as desired. The pump 110is preferably contained within the tank 190 so that if a leak occurs inthe pump 110 or associated line it will be contained in the tank 190.

To prevent sediment buildup in the tanks 160, 170 and 190, third andfourth air pumps 120 and 124 are connected to agitators 140 and 142 vialines 141 and 142 to pump recycled wash solution in tank 190 to thetanks 160, 170 and 190. The pumps 120 and 124 are connected to thedistribution tee 700 by associated lines 704 and each has an associatedvalve and filter 706 to regulate the flow of wash liquid. While airpumps are preferred, any type of pump can be used as desired. The pumps120 and 124 are preferably contained within the tank 190 so that if aleak occurs in the pumps or associated lines it will be contained in thetank 190. Preferably, two pumps 120 and 124 are used in case one pumpfails and stops flow to one set of agitators 141 or 142, the other pumpwill supply flow the other set of agitators and agitate the washsolution in each tank 160, 170 and 190.

As shown in FIG. 10, the agitators 140 are formed from a 1 inch squarepipe that has been capped at both ends. A plurality of ¼ to ⅜ inch holes145 are spaced the length of the agitators 140. The agitators 142 can beformed in the same manner as agitators 140. When recycled wash solutionis pumped into the agitators 140, it is sprayed out of the holes 145 andagitates the wash solution present in the tanks 160, 170 and 190. Theagitator 142 works in the similar manner. The size, shape and number ofthe agitators 140 and 142 can be varied as desired for the particularapplication. If more agitation is desired, a larger agitator, multipleagitators or smaller holes 145 can be used. If less agitation isdesired, a smaller agitator or larger holes 145 can be used. Ifprecipitates form in the recycled wash solution tank 190 they can bepumped into the holding tanks 160 and/or 170 via the agitators 140 and142 and then caught by the respective filter assemblies. The agitatorscan be run continuously, even when the spray washer is not used, toremove undesirable precipitates and prevent sediment buildup in thetanks.

If desired, wash solution from the holding tank 170 can be used tosupply the agitators 140 and 142 in the holding tank 160. However,recycled wash solution from tank 190 is preferably supplied to at leastone of the agitators in the tanks 150, 160 or 170 so that ifprecipitates form in the recycled wash solution in tank 190 they can befiltered by any of the filter assemblies 162, 172 or 182.

The recycled wash solution in tank 190, and tank 8 as described above,may form liquid and sediment layers over time. To prevent these layers,the recycled was solution can be stirred once a day and/or an agitatoror stirrer can be added to tanks 8 and 190. Furthermore, the recycledwash solution in tanks 8 and 190 can be withdrawn from a location offthe bottom of the tanks 8 and 190 to reduce clogging from sediment, suchas about 1 to 6 inches, more preferably about 2 to about 4 inches, fromthe bottom.

The recycling apparatus 100 preferably contains a water level monitor200 in the recycled wash solution tank 190 to alert the user of low washsolution conditions. If desired, the water level monitor 200 can beconnected to a water supply to automatically add water to the recycledwash solution tank 200 through inlet 202 as needed. The water levelmonitor 200 can be any conventional water level monitor, such ascommonly used in toilets or the well-known water levelers used in thecommercially available Swamp Cooler™.

During operation, the recycling apparatus 100 is connected to powerwashers 800 using hose 802. The pump 110 pumps recycled wash solution tothe power washers 800 at a pressure of about 5 pounds per square inch(psi) or greater. The capacity of the pump 100 can be adjusted to matchthe input pressure requirements of the number and type of spray washersbeing utilized. The power washers 800 heats the wash solution to anydesired pressure and temperature, for example, about 180 to about 220°F. and about 1500 to about 3000 psi. The object to be washed is sprayedwith the heated pressurized wash solution in the wash areas 810 usingthe wands 806. The used wash solution is collected and the dirtseparated therefrom using the screens 811. The screened used washsolution is then pumped to the inlet 151 of the recycling apparatususing the pumps 812 and line 814 in a continuous loop.

During operation, it has been found that the pH of the recycled washsolution can vary. Preferably, the recycling apparatus comprises a pHmonitor 210 located on the phosphate tank 211 and having a pumpassociated therewith which monitors the pH of the recycled wash solutionin the recycled wash solution tank 190 using the probe 214. If the pH istoo high, the pH monitor adds phosphate to the recycled wash solutiontank 190 via phosphate inlet 218 until the desired pH is reached.However, the pH can also be monitored and adjusted manually if no pHmonitor is present.

Preferably, the pH of the wash solution in the recycled wash solutiontank 190 is maintained such that it is high enough to avoid causingsignificant rust on the part being cleaned and low enough to providesufficient cleaning. It has been found that when phosphate is used, thepH should be between 4.5 and 6.5, more preferably between about 5 toabout 6, and most preferably about 5.5 to provide sufficient cleaningand avoid causing significant rust on the part being cleaned. The pH canbe easily measured using well-known litmus strips or electronic pHmeasuring equipment. These pH ranges apply to a powder coating processutilizing phosphate. If other chemicals are used, or different cleaningtechniques are utilized, the pH can easily be tailored to any desiredrange by using common techniques of adding bases to increase the pH andacids to decrease the pH.

The wash solution can be monitored for phosphate concentration using atitration test. The test can be conducted using commercially availablekits comprising reagents, beakers and droppers with instructions on howto use the reagents to measure the phosphate concentration. If thephosphate concentration is too high, water can be added, or conversely,if the phosphate concentration is too low, phosphate can be added. Theconcentration of phosphate will vary for the particular application. Theamount of phosphate should be low enough to avoid leaving a visibleresidue on the cleaned part and high enough to provide sufficientcleaning. Suitable amounts of phosphate may vary with the hardness ofwater used and other chemicals present. Suitable phosphateconcentrations, for example, are less than 4%, preferably 2 to 2.5% byvolume based on the total volume of the wash solution. However, oneskilled in the art will easily be able to determine a suitable phosphateconcentration based on the disclosure provided herein.

Preferably, no high-voltage electricity is utilized in the recyclingapparatus 100 to provide enhanced safety. In this regard, the pumps 110,120, 124 and 126 are all pressurized air operated pumps. Commercialexamples of suitable air operated pumps include those sold under theIngersoll-Rand ARO line, such as the Model 6660. The air operated pumpsare preferably mounted inside the recycled wash solution tank 190 sothat if there are any leaks in the pump 61 they will be contained.However, if desired, the pumps can be mounted external to the recyclingapparatus 100. Conventional powder coating operations usually utilize anair compressor that can be easily tapped to power the pumps.

The lid 101 covers the main tank 102 and protecting tank 104 and ispreferably of a see-thru type material to allow easy visual inspectionof the filter assemblies and the fluid levels during operation. The lid101 can be one solid piece or multiple pieces so that access to eachholding tank can be separately obtained. The lid 101 can be hinged ifdesired, but is preferably slidably mounted or mounted to be lifted offto allow easy and safe access to the filters and the separator areas.Preferably, the lid 101 does not form an airtight seal in the main tank102 so that the pressure in the main tank 102 can equalize with theambient air pressure.

Conventional spray washers 800 have two inputs, fresh water input 815and chemical input 816. However, when the present recycling apparatus isutilized, the recycled wash solution containing chemicals is supplied tothe spray washer 800 through the fresh water input 815. The chemicalinput 816 and associated metering unit 817 can be removed since they areno longer needed, which usually results in a desired increase ofpressure at the spray wand 806. By using the present recyclingapparatus, a less complicated spray washer 806 can be utilized that doesnot have a chemical input 816 and metering unit 817 since the chemicalscan be added to the recycling apparatus.

The coil for heating fresh water in the spray washer 800 usuallyconsists of black pipe 817 and brass fittings 818, which can be corrodedby the chemicals present in the wash solution. Thus, preferably, ifpresent, the black pipe 817 and brass fittings 818 are replaced withstainless steel or another material that does not corrode in thepresence of the chemicals.

Galvanized materials should not be spray washed when using 1 micron orlarger size final filters in the recycling apparatus since theconcentration of zinc can undesirably build up in the recycler and causea hazardous situation. Galvanized materials should only be spray washedunder extreme caution to monitor and remove zinc from the recyclingapparatus.

However, it has now been found that when using a 0.2 micron final stage(2^(nd) stage and/or 3^(rd) stage in 3 stage recycling apparatus)filter, surprisingly zinc and other heavy metals such as lead andmolybdenum were removed from the wash solution. Thus, galvanizedmaterials, and other materials containing heavy metals, can now besafely power washed without causing hazardous buildup of heavy metals inthe wash solution. Furthermore, to make the present process even moreenvironmentally friendly, the used filters containing the heavy metalscan be air dried and the combined with scrap powder paint swept up fromthe floor and fired in the powder coating oven to form a brick thatbinds up the heavy metals. In this process, heavy metals are not washeddown city sewers nor disposed of in a manner in which free heavy metalscan contaminate ground water or soil. The 0.2 micron final stage filtermade the wash solution so clear in the recycling apparatus that thefloor of the tank was clearly visible through the wash solution. The 0.2micron final stage filter also removed bacteria. A preferred setup, is a3 to 5 micron filter for the first stage, and 1 micron or 0.2 micronfilters for the second and third stages depending on what material isbeing washed.

The recycling apparatus and method described herein is environmentallyfriendly. Bacterial and fungus buildup in the recycling apparatus issubstantially avoided without the use of environmentally unfriendlychemicals by a combination of the see through lid that allows light toenter, the continuous aeration in each of the tanks and filtering. Thephosphate, which is the same type (only stronger) as used in laundry anddish washers as a cleaning and disinfecting agent, will help kill thebacteria. Furthermore, the high temperature achieved in the power washerwill kill even more bacteria.

A common test used to detect potential coating failures caused by saltsremaining on the surface of the part to be coated after spray washing isdescribed in Frauman, AEffects of impure rinse water on coatingperformance, @ Morton Powder Coatings brochure. The peel resistance testcomprises:

-   -   1. Pre-treat, coat and cure a small representative test panel,        taking care to ensure the powder coating is applied and cured        consistent with the manufacturer's recommendations.    -   2. Immerse half of the coated, cured test panel in distilled        water for 24 hours at ambient temperature.    -   3. Remove and towel dry the test panel.    -   4. After sufficient ambient dwell time to ensure that the coated        surface is dry, complete, cut a cross hatch pattern in the        powder coating with a knife and apply tape. Pull the tape from        the panel and observe if any pant was removed with the tape.    -   5. Compare results on subject test panel to past typical        performance. If the paint coating separated, the coating failed.

I ran a trial to determine the how long the recycling apparatus couldrun without changing emptying and refilling with clean water andphosphate chemicals before the parts were not sufficiently cleaned. Arecycling apparatus 1 as shown in FIG. 1 was run for 1.5 months, duringwhich I used bout 2000 gallons of water and about 10 gallons ofphosphate chemicals. Without the recycling apparatus, I would have usedabout four to five 55-gallon drums of phosphate over this time periodand about 15,000 to 18,000 gallons of water.

Over the 1.5 month period, I noticed that significant amount of saltsprecipitated in the filters, which were changed twice a week. I believethe combination of acid and aeration caused the salts to precipitate outof the wash solution and be trapped in the cloth filters. However, theclaimed invention is not limited to this theory as to why the saltprecipitates out of solution in my apparatus. This precipitation causedthe salt concentration to remain low enough during this 1.5 month runthat there were no visible salt deposits on parts cleaned using therecycled wash solution. Salt deposits can adversely affect the bondingof the powder coat to a part.

Each week during the 1.5 month period, I spray washed three by six inchsheet metal panels with the recycled wash solution, after which theyexhibited a desired bluish or gold tint with no visible residues orrust. The cleaned panels were powder coated and cured. A knife was usedto cut a cross hatch pattern in the powder coated panels and then ducttape was applied. When the duct tape was ripped off of the panels, nopaint pulled off with tape. The panels were also struck with a hammerand bent with no visible peeling of the paint. The recycled washsolution provided excellent adhesion of the paint to the panel.

The recycling apparatus was then used for another month withoutreplacing the wash solution present therein, with weekly cross-hatchtesting. At 2.5 months, the cross-hatch test failed and the paint peeledfrom the surface of the panels when the tape was removed. At that time,streaks were seen on the cleaned parts, which were not evident inearlier tests. Over the 2.5 month period I only used about 20 gallons ofphosphate chemicals. While the apparatus provided sufficient cleaningwith replacement of the wash solution present therein for a period of 2months and 1 week, I recommend monthly replacements of the was solutionpresent within the recycling apparatus.

Conventional spray washing apparatus do not accurately maintain the pHand phosphate concentration of the wash solution since the phosphate isadded along with the fresh water during washing. During use monitoringand adjustment of pH on a fresh water system is very difficult. I havefound that too little phosphate and too high of a pH (higher than 6)does not provide adequate washing of the part to be powder coated.Conversely, if too much phosphate is added, the pH will be too low (lessthan 5) and phosphate remains on the cleaned part. If the part is notcleaned properly or has phosphate deposits thereon, the paint may notadequately adhere to the part and may peel during the peel testdescribed herein above. By using the recycling apparatus, the amount ofphosphate and pH can be accurately maintained.

I conducted another test over the last year during which I only used 75gallons of phosphate. In contrast, without the recycling apparatus Iwould have used 1,980 gallons of phosphate over that same year period.

The invention has been described for use in recycling wash solutions inspray washing for powder coating applications. However, the recyclingapparatus can be used to recycle wash solutions from conventional spraywashers, car washes, steam washers and laundry machines. Further, it hasbeen found that the recycling apparatus may remove salt from water andmay be useful in removing salt from sea water to provide a salt reducedwater which can be further treated, with for example reverse osmosis orother technology, to remove the remaining salt to provide fresh water.Thus, the invention is applicable whenever recycling of water and/orchemicals present in the water is desired.

While the claimed invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to one ofordinary skill in the art that various changes and modifications can bemade to the claimed invention without departing from the spirit andscope thereof.

1. A recycling apparatus for recycling used wash solution from a powerwasher used in powder coating comprising: a main tank constructed andarranged to hold a wash solution; a first baffle in said main tankdefining a first holding tank constructed and arranged for holding afirst filtered wash solution containing phosphate, said first bafflehaving a first outlet through which the first filtered wash solution canflow; a first filter assembly in gravity feed relation with the firstholding tank and being constructed and arranged such that duringoperation the wash solution filters through the first filter assembly toform a first filtered wash solution and drops into the first holdingtank a first distance before contacting first filtered wash solutioncontained therein, the first distance being sufficient to aerate a firstfiltered wash solution contained in the first holding tank duringoperation, said first filter assembly having a size of about 10 micronsor less; a second baffle in said main tank, a second holding tank beingdefined between said first and second baffles and said main tank andbeing constructed and arranged for holding a second filtered washsolution, said second baffle having a second outlet through which thesecond filtered wash solution can flow, said second outlet beingdisposed lower in height from a bottom of the main tank than said firstoutlet; a second filter assembly in gravity feed relation with thesecond holding tank and being constructed and arranged such that duringoperation the first filtered wash solution flows out of the first outletand enters and flows through the second filter assembly to form a secondfiltered wash solution and drops into the second holding tank a seconddistance before contacting a surface of the second filtered washsolution contained therein, the second distance being sufficient toaerate a second filtered wash solution contained in the second holdingtank during operation, said second filter assembly having a size ofabout 10 microns or less; a recycled wash solution tank being defined bysaid main tank and said second baffle or another baffle if additionalholding tanks are present, said recycled wash solution tank beingconstructed and arranged for holding recycled wash solution; a thirdfilter assembly in gravity feed relation with the recycled wash solutiontank and being constructed and arranged such that during operation thesecond filtered wash solution flows out of the second outlet and entersand flows through the third filter assembly to form a recycled washsolution and drops into the recycled wash solution tank a third distancebefore contacting a surface of recycled wash solution being containedtherein, the third distance being sufficient to aerate recycled washsolution contained in the recycled wash solution tank during operation,said third filter assembly having a size of 10 microns or less; a pumpconstructed and arranged to provide pressurized recycled wash solutionfrom the recycled wash solution tank of a pressure sufficient to operatea pressurized washer apparatus connected to the recycling apparatus,wherein the filter assemblies are constructed and arranged to provide atleast a 5 gallon per minute flow rate using ambient pressure and gravityflow through the filters; and at least one agitator in at least oneholding tank to prevent sediment buildup, wherein the apparatus isconstructed and arranged such that during operation recycled washsolution from the recycled wash solution tank is supplied to at leastone of the agitators so that if any precipitates form in the recycledwash solution they can be removed by one of the filtering assemblies. 2.A recycling apparatus according to claim 1, wherein the first holdingtank comprises an inlet having a disconnect and a distributing pipeconnected to the inlet that distributes the wash solution over the firstfilter assembly.
 3. A recycling apparatus according to claim 1, whereinthe height of the first outlet through the first baffle is higher thanthe second outlet through the second baffle.
 4. A recycling apparatusfor recycling used wash solution from a power washer used in powdercoating comprising: a main tank constructed and arranged to hold a washsolution; a removable first holding tank constructed and arranged forholding a first filtered wash solution containing phosphate and having afirst outlet through which the first filtered wash solution can flow; afirst filter assembly in gravity feed relation with the first holdingtank and being constructed and arranged such that during operation thewash solution filters through the first filter assembly to form a firstfiltered wash solution and drops into the first holding tank a firstdistance before contacting first filtered wash solution containedtherein, the first distance being sufficient to aerate a first filteredwash solution contained in the first holding tank during operation, saidfirst filter assembly having a size of about 10 microns or less; asecond removable holding tank constructed and arranged for holding asecond filtered wash solution and having a second outlet through whichthe second filtered wash solution can flow, said second outlet beingdisposed lower in height from a bottom of the main tank than said firstoutlet; a second filter assembly in gravity feed relation with thesecond holding tank and being constructed and arranged such that duringoperation the first filtered wash solution flows out of the first outletand enters and flows through the second filter assembly to form a secondfiltered wash solution and drops into the second holding tank a seconddistance before contacting a surface of the second filtered washsolution contained therein, the second distance being sufficient toaerate a second filtered wash solution contained in the second holdingtank during operation, said second filter assembly having a size ofabout 10 microns or less; a recycled wash solution tank being defined bysaid main tank and removable holding tanks present in the main tank; athird filter assembly in gravity feed relation with the recycled washsolution tank and being constructed and arranged such that duringoperation the second filtered wash solution flows out of the secondoutlet and enters and flows through the third filter assembly to form arecycled wash solution and drops into the recycled wash solution tank athird distance before contacting a surface of recycled wash solutionbeing contained therein, the third distance being sufficient to aeraterecycled wash solution contained in the recycled wash solution tankduring operation, said third filter assembly having a size of 10 micronsor less; a pump constructed and arranged to provide pressurized recycledwash solution from the recycled wash solution tank of a pressuresufficient to operate a pressurized washer apparatus connected to therecycling apparatus, wherein the filter assemblies are constructed andarranged to provide at least a 5 gallon per minute flow rate usingambient pressure and gravity flow through the filters; and at least oneagitator in at least one holding tank to prevent sediment buildup,wherein the apparatus is constructed and arranged such that duringoperation recycled wash solution from the recycled wash solution tank issupplied to at least one of the agitators so that if any precipitatesform in the recycled wash solution they can be removed by one of thefiltering assemblies.
 5. A recycling apparatus according to claim 4,further comprising a stand for holding said third filter assembly,wherein when said first and second tanks are in operation positionwithin said main tank, said second outlet empties into said third filterassembly.
 6. A recycling apparatus according to claim 4, furthercomprising an oil separator tank that is removable from the main tank,wherein the oil separator tank comprises an oil skimmer and an intake ata lower portion of the oil separator tank for supplying oil reduced washsolution to said first filter assembly during operation.
 7. A recyclingapparatus according to claim 6, further comprising at least one agitatorin the oil separator tank to prevent sediment buildup.
 8. A recyclingapparatus according to claim 4, further comprising a protecting tankthat surrounds the sides of the main tank.
 9. A recycling apparatusaccording to claim 8, wherein said protecting tanks comprises removablepanels such that if the protecting tank is damaged it can be repaired byreplacing one or more removable panels.
 10. A recycling apparatusaccording to claim 1 or 4, wherein the agitator comprises a pipe havinga plurality of holes connected to the pump such that during operationrecycled wash solution flows from the recycled wash solution tank to theagitator and out the holes to agitate the filtered wash solution presentin the holding tank.
 11. A recycling apparatus according to claim 1 or4, wherein each filtering assembly is removable.
 12. A recyclingapparatus according to claim 1 or 4, wherein each filtering assembly isadjustable in height such the distance the filtered wash solution dropsinto a filtered wash solution being contained in a holding tank isadjustable.
 13. A recycling apparatus according to claim 1 or 4, whereineach filtering assembly comprises a mesh screen and means for holding afilter in place.
 14. A recycling apparatus according to claim 13,wherein the filter comprises a sheet of filter cut to length.
 15. Arecycling apparatus according to claim 1 or 4, wherein the tanks havesee through lids for monitoring the filtering assemblies duringoperation.
 16. A recycling apparatus according to claim 1 or 4, whereinthe tanks are covered by a see through lid for monitoring the filteringassemblies during operation.
 17. A recycling apparatus according toclaim 1 or 4, wherein the apparatus is constructed of materials suitablefor use at a low pH and containing phosphate.
 18. A recycling apparatusaccording to claim 1 or 4, wherein said first, second and third distancethe filtered wash solution drops is from about 1 to about 30 inches. 19.A recycling apparatus according to claim 1 or 4, wherein said first,second and third distance the filtered wash solution drops is from about2 to about 24 inches.
 20. A recycling apparatus according to claim 1 or4, wherein said first, second and third distance the filtered washsolution drops is from about 3 to about 12 inches.
 21. A recyclingapparatus according to claim 1 or 4, wherein said first, second andthird distance the filtered wash solution drops is from about 6 to about8 inches.
 22. A recycling apparatus according to claim 1 or 4, whereinthe first holding tank has a plurality of outlets and each outlet isconnected to a pipe such that the first filtered wash solution isdistributed over the second filter assembly.
 23. A recycling apparatusaccording to claim 22, further comprising four outlets and pipesconnected to the first holding tank which are spaced out along the widthof the first filter assembly and the pipes terminate at about a midpoint axis of the first filter assembly.
 24. A recycling apparatusaccording to claim 1 or 4, wherein the second holding tank has aplurality of outlets and each outlet is connected to a pipe such thatthe first filtered wash solution is distributed over the third filterassembly.
 25. A recycling apparatus according to claim 24, furthercomprising four outlets and pipes connected to the second holding tankwhich are spaced out along the width of the second filter assembly andthe pipes terminate at about a mid point axis of the first filterassembly.
 26. A recycling apparatus according to claim 1 or 4, whereinthe first filtering assembly has a filter size of about 3 to 8 micronsand the second and third filtering assemblies have a filter size ofabout 1 microns.
 27. A recycling apparatus according to claim 1 or 4,further comprising a plurality of holding tanks and filter assemblies incommunication with the holding tanks.
 28. A recycling apparatusaccording to claim 1 or 4, further comprising a means for measuring pHand automatically supplying pH adjusting chemicals to maintain a desiredpH in the recycled wash solution during operation.
 29. A recyclingapparatus according to claim 28, wherein the means for measuring pHadjusts the pH by adding phosphate to the recycled wash solution duringoperation.
 30. A recycling apparatus according to claim 1 or 4, furthercomprising means for automatically adding water to adjust the level ofwash solution in the recycled wash solution tank.
 31. A recyclingapparatus according to claim 1 or 4, further comprising a power washerconnected to said pump.
 32. A method of recycling wash solution from apower washer used in powder coating comprising: filtering wash solutionthrough a first filter assembly under ambient pressure to form a firstfiltered wash solution and allowing the first filtered wash solution todrop a first distance into a first holding tank before contacting asurface of the first filtered wash solution being containing in thefirst holding tank, the first distance being sufficient to aerate thefirst filtered wash solution in the first holding tank; filtering thefirst filtered wash solution through a second filter assembly underambient pressure to form a second filtered wash solution and allowingthe second filtered wash solution to drop a second distance into asecond holding tank before contacting a surface of the second filteredwash solution being contained in the second holding tank, the seconddistance being sufficient to aerate the second filtered wash solution inthe second holding tank; filtering the second filtered wash solutionthrough a third filter assembly under ambient pressure to form arecycled wash solution and allowing the recycled wash solution to drop asecond distance into a recycled wash solution tank before contacting asurface of the recycled wash solution being contained in the recycledwash solution tank, the first distance being sufficient to aerate therecycled wash solution in the recycled wash solution tank; pressurizingthe recycled wash solution to a pressure sufficient for a power washer;supplying the pressurized recycled wash solution to a power washer whichheats and further pressurizes the recycled wash solution; washing anobject to be powder coated with the heated and pressurized recycled washsolution; collecting wash solution from the washing step; screening thecollected wash solution to remove dirt particles; and supplying at leasta portion of the screened wash solution to the first filter assembly forrecycling.
 33. A method according to claim 32, further comprising thestep of continuously monitoring the pH of the recycled wash solution inthe recycled wash solution tank and automatically adding phosphate asneeded to retain a desired pH.
 34. A method according to claim 32,further comprising the step of continuously monitoring the level of washsolution in the recycled wash solution tank and automatically addingwater as needed.
 35. A method according to claim 32, further comprisingtransferring recycled wash solution from the recycled wash solution tankto at least one of the first holding tank or second holding tank toagitate the filtered wash solution present in the first holding tankand/or second holding tank and to remove precipitates formed in therecycled wash solution tank.
 36. A method according to claim 32, furthercomprising the step of removing oil from the wash solution prior tofiltering through the first filter assembly.
 37. A method according toclaim 32, further comprising using a 0.2 micron filter in the thirdfilter assembly to remove heavy metals from solution.
 38. A methodaccording to claim 37, further comprising drying the 0.2 micron filterafter it collected heavy metals, combining the dried 0.2 micron filterwith powder coating materials, and firing the 0.2 micron filter andpowder coating materials in an oven to bind the heavy metals.
 39. Amethod according to claim 38, wherein the powder coating materials arewaste powder coating materials collected from the floor following powdercoating an object.